How do you define end-stage renal disease?

See Below. End stage renal disease is stage five ckd or GFR 15 or less. Dialysis is started when the function of the kidneys is inadequate to remove the metabolic byproducts of metabolism. In practice this is usually determined by measuring gfr. Most people have to start dialysis when GFR drops to 10-15 though it may have to be started higher or lower than that.
GFR < 15. Any patient with a GFR (glomerular filtration rate) of less than 15 or on permanent renal replacement therapy (hemodialysis or peritoneal dialysis) is considered esrd.